A conventional wrench structure with a rotatable gripping member at the rear end of the wrench, such as U.S. Pat. No. 4,699,028 whose wrench structure is so designed that the end of the connecting grip of the wrench controls a 360° rotation. The pinion gear inside the connecting grip can be rotated. The pinion gear engages the gearwheel mounted in the rotating member. Thus, the gearwheel and the rotating member can jointly rotate. A raised coupling end is provided on the rotating member. The coupling end can couple a socket, and lock the coupling member by rotation.
The advantage of above mentioned prior art is when the wrench cannot be turned due to the limitation of the work space, the user can turn the pinion gear at the end of the connecting grip of the wrench so as to jointly drive the gearwheel and the rotating member. Thus, the space limitation can be solved. However, the connecting grip of the conventional wrench is with a fixed shape. If the work space is narrow and winding, it is difficult to use the wrench.